reject zero-length padded DATA frame in H2Context::OnData#3325
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sahvx655-wq wants to merge 1 commit into
Open
reject zero-length padded DATA frame in H2Context::OnData#3325sahvx655-wq wants to merge 1 commit into
sahvx655-wq wants to merge 1 commit into
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wwbmmm
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Jun 5, 2026
| H2ParseResult H2Context::OnData( | ||
| butil::IOBufBytesIterator& it, const H2FrameHead& frame_head) { | ||
| const bool has_padding = (frame_head.flags & H2_FLAGS_PADDED); | ||
| if (frame_head.payload_size < (size_t)has_padding) { |
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The logic is not clear to converter a bool to a size_t here
| uint32_t frag_size = frame_head.payload_size; | ||
| uint8_t pad_length = 0; | ||
| if (frame_head.flags & H2_FLAGS_PADDED) { | ||
| if (has_padding) { |
Contributor
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I think a better way is to add the check code here:
if (frag_size <= 0) {
LOG(ERROR) << ...
return ...;
}
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A DATA frame with the PADDED flag but Length 0 underflows frag_size here.
--frag_sizewraps the uint32_t to 0xFFFFFFFF, thefrag_size < pad_lengthcheck then passes, and the bogus size reaches append_and_forward, which swallows the rest of the connection buffer as one DATA payload and feeds ~4GiB into the flow-control counter. OnHeaders already rejects this case; OnData was missing the same guard. Fix returns FRAME_SIZE_ERROR per RFC 7540 6.1 when a padded frame has no room for the pad-length byte.